This invention relates generally to closure actuated lamp switches and, more particularly, to a lamp switch and connector means assembly contained within an integral housing preferably suitable for installation in automobile glove boxes.
In automobiles, closure actuated switches are typically installed to control lamps or bulbs which illuminate the interiors of glove boxes or other compartments only when the compartments are open. Generally, closure actuated switches operate by means of a plunger to close and open a circuit. The plunger causes electrical contacts of opposite polarity in the electrical circuit either to engage each other directly or to be bridged in some fashion by a connecting means. Friction between opposing poles of an open circuit occurs generally in such switches when the opposing poles are moved into direct contact with each other or with a bridging means to complete the circuit. When opposing poles are biased, friction between them or a bridging means will be greater. The friction tends to cause wear and tear on the opposing poles which, in turn, often decreases the usable life of the switch. Repeated usage may strain the biased poles beyond their resiliency, thereby impairing the ability of the opposing poles to provide a stable electrical connection.
Known closure actuated switches have utilized plunger-type means to complete an electric circuit to light a lamp or bulb. For example, U.S. Pat. No. 2,646,477 discusses a closure actuated switch wherein a single terminal or tab of metal near the lamp portion of the assembly is connected to the ungrounded portion of an automobile battery. The grounding terminal is located at the plunger portion of the assembly and grounds the circuit through a metal frame located within the glove box. Accordingly, the terminals are located at opposite ends of the assembly. The switch completes an electrical circuit through movement of a plunger which brings two electrical contacts of opposite polarity into direct contact. A spring biasing means which forces the plunger to an extended position, thereby connecting the two electrical contacts, is part of the electrical circuit as it electrically connects the bulb with one of the electrical contacts.
An electrical switch is discussed in U.S. Pat. No. 4,384,181 wherein a conductive sleeve is positioned on a rod section of a plunger. The conductive sleeve contacts two terminals which are biased toward the conductive sleeve. The conductive sleeve travels a length of the biased terminals when engaging and disengaging them.
A combined illumination and minimum temperature control for refrigerators is discussed in U.S. Pat. No. 2,658,968. The control assembly is composed of a contact ring positioned on a plunger so as to make contact with terminals. The terminals are movable in response to temperature conditions within the refrigerator. A lamp is mounted on the back wall of the refrigerator remote from the control assembly. Also connected to the control assembly is a temperature-sensing unit. The control assembly lights the remote lamp even when the refrigerator door is not open to increase the temperature within the refrigerator.
A drawback of known closure actuated switches is their reliance upon sliding contact between nonstationary opposing poles either directly or through a bridging means to complete a circuit. The poles to be connected are often biased, requiring them to be strained upon making electrical contact. The resulting friction may produce wear and tear upon the poles themselves. Additionally, a problem arises when biased poles are strained by use beyond their resiliency. The poles may not retain enough resiliency to maintain stable electrical contact leading to premature failure of the circuit.
Therefore a need exists to provide a lamp switch and connector assembly which is integral in design, and preferably suitable for installation in automobile glove boxes. It is a particular object of an embodiment of the present invention to provide a closure actuated lamp switch and connector means assembly comprising an integral housing and a plunger-type actuating means. Other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.